HTML indenter written in Python

I am looking for a free (as in freedom) HTML indenter (or re-indenter) written in Python (module or command line). I don't need to filter HTML with a white list. I just want to indent (or re-indent) HTML source to make it more readable. For example, say I have the following code:

<ul><li>Item</li><li>Item
</li></ul>

the output could be something like:

<ul>
    <li>Item</li>
    <li>Item</li>
</ul>

Note: I am not looking for an interface to a non-Python software (for example Tidy, written in C), but a 100% Python script.

Thanks a lot.